Anthony Santos used to work out at his gym in New York’s Chelsea neighborhood relatively unrecognized. Other than the gym’s Latino staff members, few ever noticed the Bronx native. That changed three years ago when ads featuring Santos — aka Romeo Santos, lead singer of the internationally known bachata band Aventura — began popping up around the city promoting the group’s upcoming concerts.

His days of working out at his gym incognito were over.

“These guys who never looked at me in the past were now watching me while they ran on their treadmills,” said Santos, barefoot in his Park Hyatt Chicago hotel room Tuesday hours before an album-signing event downtown at FYE. “It felt kind of weird. One day, this girl came up to me at the gym and said, ‘I could have sworn I saw your face on the bus today.’ Just to mess with her, I said ‘No, that’s not me.’”

These days, the 30-year-old singer is still mostly unknown to non-Latinos in the United States. But, with a debut solo album, “Formula Vol. 1,” on the Billboard charts and his own sitcom produced by Will Smith on the way, for how much longer?

Santos presented an award to Justin Bieber at the 2010 MTV Video Music Awards and was invited to perform “Promise,” his duet with Usher off of “Formula,” on ABC’s ““Dancing with the Stars”” (he declined because of schedule conflicts but did perform the song with Usher at the Latin Grammys Nov. 10). “Formula Vol. 1,” which debuted at No. 9 on the Billboard 200 Tuesday, also includes cameos from Lil Wayne and Pitbull.

While the album features more English than your typical, predominantly Spanish Aventura album, Santos, born to a Puerto Rican mother and Dominican father, said he doesn’t consider himself a true crossover artist. He believes the audience is crossing over to him more than he is crossing over to it.

“Some of my songs are Americanized, but it’s still a bachata album. I could have gone in different directions with Usher, but I chose bachata,” he said.

In 2012, Santos plans to make his acting debut in an as-yet untitled comedy set to air on ABC. Santos will play an aspiring entrepreneur in New York whose traditional Dominican father prefers he work at the family’s restaurant. Santos said he can’t believe that someone who has only acted in music videos could land his own TV show, but box office superstar Smith himself wasn’t the most experienced actor, either, when he first starred in NBC’s “Fresh Prince of Bel-Air.”

“I’ve been able to perform in front of thousands of people on stage in a character that’s nothing like me. I’m very shy,”” said Santos, whose band sold out New York’s Madison Square Garden four times in 2010 and Los Angeles’ Staples Center twice in 2009. “That gives me the confidence to do this (TV) show.”

Santos plans on going back on the road in the near future, but it will be as a solo artist for the first time in his career. Asked if it will feel strange performing Aventura songs without the group’s three other members, Santos simply said, “No.”

“If you would have asked me that two or three months ago, I wouldn’t have an answer,” Santos said. “But I did a few private events and performed some Aventura songs since then, and it felt very organic. It didn’t feel weird at all. But I ask myself if it would be weird for the other guys since they’re doing it with another singer.”

Some fans of Aventura worry they’ve likely seen the last of the group now that everyone is off doing separate projects. It doesn’t help that Aventura’s most recent album was called “The Last.” Santos, however, claimed the band is “at a pause” and has not broken up.

“The plan right now is for us to offer our audience individual (projects),” Santos said. “At the end of 2013, we should be recording a new album.”